Admission of air to the induction pipes of internal combustion engines



July 18, 1933. E. ISDAHL 1,918,913

ADMISSION OF AIR TO THE INDUCTION PIPES OF INTERNAL COMBUSTION ENGINESFiled March 31, 1932 3 Sheets-Sheet l ifil fillllllllllllllllll I July18, 1933. E. HSDAHL 1,91,913

ADMISSION OF AIR TO THE INDUCTION PIPES OF INTERNAL COMBUSTION ENGINESFiled March 31, 1952' 3 Sheets-Sheet 2 jimzy July 18, 1933. [sDAHL1,918,913

ADMISSION OF AIR TO THE INDUCTION PIPES OF INTERNAL COMBUSTION ENGINESFiled March 31, 1932 3 Sheets-Sheet 3 Patented July 18, 1933 UNITEDSTATES PATENT. OFFICE ISDAHL, 0F OSLO, NORWAY ADMISSION OF AIR TO THEINDUCTION lPIPES OF INTERNAL COMBUSTION ENGINES Application filed March31, 1932, Serial No.

The present invention relates to apparatus for preventing the formationof a vacuum in the cylinders of internal combustion engines and moreparticularly the engines of motor vehicles of all kinds.

The invention has for its object to prevent the formation of smoke andfumes in the exhaust gases, which occurs when the throttle valve betweenthe carburetter and the cylinders is suddently closed, either when thespeed is reduced or changed.

In the two circumstances above referred to, the throttle valve is closedand this results in the production within the cylinder, in which thepistons reciprocate due to the weight of the vehicle or to the kineticenergy of the flywheel of an exceedingly high vacu-' um which both drawlubricating oil into the compression chamber and excess gasoline throughthe idle running jet.

As soon as the throttle valve is again opened and the combustiblemixture supplied to the cylinders, the excess quantity of gasoline andlubricating oil in the combustion chambers cause the presence in theexhaust gases of large quantities of GO and oil in more or less burnt orcracked condition. These half burnt oil products pass through theexhaust pipe as blue smoke which has a very unpleasant odour andpervades the sur rounding air. Attempts have been made in various waysto overcome the formation of smoke, which is particularly troublesomeinlarge towns with heavy omnibus traiiic and large numbers of privatevehicles. l'hus for example it has been proposed in the specification ofmy prior application for patent, U. S. Ser. No. 561,7 89 to provide inthe induction pipe between the throttle valve and the cylinders, a valvethe mechanism for openingwhich is positively-connected with themechanism for opening the throttle valve in such manner that thefirst-mentioned valve cannot be opened before the throttle valve isclosed and vice versa. An intermediate position of the valve has noobject and would cause the apparatus to function less satisfactorily.

A disadvantage of this apparatus consists in this that it is operatedeither entirely or partly manually, and the result obtained is 602,287,and in Norway February 11, 1932.

therefore more or less dependent on the skill and attention of thedriver.

The essential object of the present invention is an apparatus whichefi'ects automatic opening of the air valve, when the throttle valve isclosed, the said valve being automatically closed directly before orsimultaneously with the opening'of the throttle valve.

In accordance with the present invention there are used for this purposepreferably two electro-magnets or solenoids of which one, which directlycontrols the said valve, is supplied with current by a switch which iscontrolled by a vacuum indicator connected with the induction pipeleading to the cylinders in such manner that when the negative pressurein this pipe rises to a certain extent above the normal negativepressure corresponding to idle running, a circuit is closed as theresult of which the solenoid opens the valve, while the other solenoid,which operates a snap mechanism which at the moment when the valve isopened locks the latter in the open position, is connected by a contactdevice with a source of current which contact device in dependence onthe speed of rotation of the engine is controlled for example directlyby means of a centrifugal device or indirectly by means of a relay,which receives current from the usual generator associated with theengine.

As soon as the speed of the engine falls to such an extent that therelay or the centrifugal device provides a closed circuit from thesource of current to the releasing solenoid, the latter releases thevalve which is then closed and the engine is again ready to receive thecombustible mixture from the carburetter under-the control of thethrottle valve.

Should the driver of the vehicle wish to supply combustible mixture tothe engine before the speed of the engine has fallen to an extent suchas above mentioned, the valve must be closed earlier than above stated.For this purpose, in accordance with the invention a circuit is providedwhich serves also for the supply of current to the releasing solenoidand this circuit is closed mechanically, for example under the influenceof the usual throttle valve operating mechanism. In the circuit of thereleasing solenoid in order to prevent the solenoid remaining undercurrent when not desired, there is provided an auxiliary contact whichopens the circuit when the valve is closed and by which the circuit isclosed when the valve is opened.

Although the use of the other solenoid is to be preferred, it is clearthat it can be replaced by a mechanically acting locking and releasingmechanism, which for example is controlled by a centrifugal deviceand/or. a mechanical connection with the accelerator or gas pedal.

The invention is also concerned with certain details of construction ofthe automati-;

cally acting apparatus above described. In order that it may be fullyunderstood, the invention is hereinafter described with reference to theaccompanying drawings, which illustrate diagrammatically severalarrangements of theinventiontogether with an embodiment of the preferredconstruction of the automatically acting device.

In the drawings, Fig. 1 illustrates diagrammatically one form of theautomatical- 1y acting apparatus.

Fig. 2 is an end view of a preferred construction of the valve device,while Fig. 3 shows the valve device in side elevation, the differentelectric contacts and connections which are necessary for operation ofthe apparatus being indicated diagrammatically, and

Fig. 4 illustrates a modified embodiment of apparatus as showndiagrammatically in Fig. 1.

Referring to the drawings and particularly to. Fig. 1, 1 indicates thethrottle valve provided in the induction pipe 2 of an engine, not shown.The-carburetter which is also omitted from the drawings is locatedbeneath the throttle valve. Above the throttle valve there is providedin the induction pipe 2' an air supply conduit 3, which is closed to theatmosphere by means of a valve 4, movable in a vertical direction. Thevalve 4 is connected at its upper end with an armature 5 which can movein a vertical direction in an electro-magnet coil 6.

There is also provided a releasing magnet 30 with an armature 31 whichis under the influence of a helical spring 32 tending to push thearmature'31 outwards. The electromagnet 6 and the releasingelectromagnet 30 are arranged in such relation to one another that thearmature 31, when the armature 5 is attracted, drops into a recess 34 inthe armature 5 and will thus lock the valve 4 in open position. In orderthat the valve 4 can fall again into the closed position, the armature31 must be retracted. The electromagnet 6 is earthed by means of aconductor 35 and is connected by means of a conductor 36 with a switchdevice 37 in a vacuum indicator 38. The vacuum indicator 38 is connectedby means of a conduit 39 with the induction pipe 2 above the throttlevalve 1.

The other side of the switch device 37 is connected by means of aconductor 40 with the battery 24, the other 'end of which is earthedby'the line 41. When the pressure decreases 1n the induction pipe 2 to acertain extent, the diaphragm 42 is drawn downwards and an electricconnection effected between the contacts in the switch device 37 so'thata circuit isformed from earth at one end through the line 41, battery24, line 40, contact device 37, line 36, coil of the electromagnet 6 andline 35 to earth. The armature 5 is thereby raised and the armature 31engages in the recess 34 and holds the valve open in this position. Assoon as the valve 4 is opened, the pressure in the induction pipe 2increases and the electric connection through the switch device 37 isinterrupted. The supply of current to the electromagnet 6 will thereforeonly continue for a moment or two.

It is assumed that the vehicle at this moment is driving the engine at ahigher speed than the idle running speed of the engine. As the vehicleis braked. the speed of the vehicle and consequently the speed ofrotation of the engine also falls. When the speed of rotation of theengine falls to the usual idle running speed, there is no longer anyreason for holding the valve 4 open.- At this moment it is thusdesirable that current should be supplied to the releasing magnet 30 andfor this purpose according to the invention a centrifugally controlledswitch device 43 may be provided, which is connected directly orindirectly with the crank shaft of the engine. When the centrifugalweights fall due to the fall in speed, an electric connection is formedby the contact plate 44 between the contacts 45 and 46. The contact 46is connected by means of a line 47 with the one side of the battery 24and the contact 45 is connected by means of a line 48 with a contact 49,which, when the armature 5 is attracted, is connected by means of acontact plate 50 with a contact 51 which is connected by means of a line52 with the coil of the electromagnet 30, the other side of which isearthed by means of line 53. At this moment, therefore, the armature 31is retracted and the armature 5 will fall and the valve 4 will close theair supply inlet 3 and the engine will operate in the usual manner. Whenthe armature 5 falls, the connection between the contacts 49 and 51 willconsequently be interrupted as the contact plate 50 falls with thearmature. The supply of current to the releasing magnet 30 will thusonly be momentary.

In order that the driver may set the engine at normal running before thespeed of the contact device 55 which is controlled by the accelerator orgas pedal 56 and which will provide a connection between line 57 whichwill supply current to the coil through the contact 49, plate 50,contact 51, and line 52 and will release the armature 5, when theaccelerator or gas pedal 56 is depressed so that the valve 4 is closedand the engine can be driven in the normal way.

In Fig. 4 the same apparatus is shown; but here the release mechanism isarranged to operate mechanically instead of electricall For this purposethe centrifugal mechanism 43 is arranged to act against an arm and bellcrank system 90, 91, 92, for retracting the plunger 31 from itsengagement with the armature 5.

And another system of arm and bell cranks 93, 94, 95 serves to connectthe gas pedal with the release mechanism. It may here be good to arrangea resilient connection 96 to take up unnecessary movements of the parts.

til

The operation of this embodiment is selfevident for anybody, afterhaving studied the operation of the embodiment shown in F i 1 in theabove description.

ft will thus be understood that when the difierent devices have oncebeen fitted in place and have been adjusted to suit the requirements ofthe engine, they will operate entirely automatically without theoperator requiring to do anything to the mechanism himself.

In Figs. 2 and 3 is shown a detailed em bodiment of a preferredconstruction of the mechanism which has been described diagrammaticallyabove.

][n Fig. 3 the mechanism is shown also in conjunction withdiagrammatically shown electric connections which indicate how the Wholeapparatus works.

The embodiment illustrated in Figs. 2 and 3 is intended for use inconjunction with an engine having two induction pipes 2', each serving agroup of cylinders. Two valves 4' are therefore provided in twocorresponding inlet pipes 3 which are connected to the induction pipes2. The valves are arranged as ordinary throttle valves, i. e. they aremounted to rotate about a spindle 58 which is operated by means oftoothed gearing hereinafter described.

The main magnet 6 is provided with an armature 5 which is provided witha bore 59, in which is provided a helical spring60 which serves to forcethe armature out of the magnet. At the outer end the armature 5 isconnected by means of a link 61 with an arm 62 which is mounted on ashaft 63, at the other end of which is provided a partly toothed disk64. The teeth 65 of this disk pinion 66 which is mounted on 58, to whichthe valve 4' is semesh with a the spindle cured.

When the armature 5' is drawn inwards, a

rotary movement is imparted to the disks 64,

which is transmitted by the teeth 65 and the pinion 66 to the spindle 58in such manner that the valve 4' is opened. In order further to ensurethat the armature 5' will be pushed outwards with sufliciently greatforce, a helical spring 67 is provided which is secured to an extension68 of the arm 62 at one end and at the other to the connecting partbetween the two induction pipes 3'. The magnet 6 is connected to theremainder of the apparatus by means of a strap or band 68.

Adjacent the magnet 6 there is provided a releasing magnet 30. Thismagnet and the part supporting it are insulated from the remainder ofthe apparatus being secured thereto by means of screws 69 which passthrough insulating sleeves 70 and bear against an insulating washer 71.In the releasing magnet 30 is provided an armature 31 which is connectedby means of a link 72 with bell crank arm 73 which is rotatably securedby means of a screw 74 to the part, to which the releasing magnet 30 issecured. At the free end arm 73 is provided with a hook 75 which whenthe valve 4 is closed, bears against an insulating plate 76. A bladespring 77 is provided which tends to press the hook 75 against the saidinsulating plate 76. In the disk 64 spaced somewhat from the insulatingplate 76 is provided a notch 78 which serves to form a stop for the hook75 when the disk 64 is rotated by the arm 62. When thus current issupplied to the magnet 6, the disk 64 will turn towards the left in thedrawings until the hook 75 engages in the notch 78 and thereby will lockthe armature 5 in the attracted position, so that the valve 4 willremain open. At the same time an earth connection is provided betweenthe releasing magnet 30 and the remaining part of the apparatus.

1 The electric control system of the above described electromagneticdevices comprises a vacuum indicator or gauge 38 with a contact device37', a relay 79, battery 24 and an accelerator or gas pedal 56. Theoperation is substantially the same as above described in connectionwith the diagrammatic example, but is hereafter again described withreference to the drawings, so that it will be clearly understood.

The one side of the electro-magnet 6' is earthed by means of line 35.The other side of the magnet 6 is connected by means of line 36 with theone side of the contact device 37 in the vacuum gauge 38'. The otherside of this contact device is connected by means of line 40' with theone side of the battery 24, the other side of which is earthed by meansciently high to do so.

of line 41'. When the negative pressure in the induction pipe 2 hasreached a certain degree, the pointer 80 will close a circuit throughthe contact device 37", so that electric energy will be supplied to themagnet 6 and the. valves 4 will be opened as above described. The hook 75 will as above described lock the valves in open position at the sametime as an earthed connection from the auxiliary magnet 30 through line53 will be effected by the hook. The other side of the releasing magnet80 is connected by means of line 52 with the one contact 45 of the relay79 and with the one contact 81 of the contact device 55' of theaccelerator or gas pedal 56. The other contact 46 of the relay 79 andthe contact 82 of the contact device 55' are both connected with oneside of the battery 24. The relay 79 which is shown in diagram form inthe drawings may be a special voltage relay, of which both ends 83 and84 are connected through the usual generator of the motor, or in somecases will be the usual device connecting the generator for charging thebattery when the speed of the generator is sufii- In both cases theoperation is the same; as'long as the generator runs at a high enoughspeed, the voltage between the two sides of the relay Will be largeenough to ensure that the contact plate 85 is not in contact with thecontacts 45' and 46'. As soon as the speed of the engine fals to apredetermined point, the voltage will be too small and an electricconnection between the two said contacts will be effected. As soon asthis happens, current is supplied to the releasing magnet from thebattery whereupon the hook 75 is raised from engagement with the notch78 and the springs 60 and 67 ensure that the valve 4' is again closed.Should the accelerator or gas pedal 56 be depressed be fore thishappens, a circuit is formed between the contact device 55' which willhave the same e'fiect as above described. In both cases the valves 4will be closed. Thus there are no current supplying conductors in thewhole system except at the moment when the apparatus is operating.

I claim 1. An apparatus for preventing the formation of a vacuum in thecylinders of an internal combustion engine when the throttle valve isclosed, comprising an opening, closed by a valve in the induction pipebetween the throttle valve and the cylinders and means to open saidvalve, when the vacuum in the induction pipe exceeds normal idle runningvacuum, said means comprising an electric magnet with an armatureconnected to said valve and a vacuum gauge, connected to the inductionpipe and controlling the circuit, through which electric current isfurnished to the said magnet, and a snap mechanism, serving to lock thesaid valve in open position and means controlled by the speed of themotor for releasing the said snap mechanism.

'2. An apparatus forpreventing the formation of a vacuum in thecylinders of an internal combustion engine when the throttle valve isclosed, comprising an opening, closed by a valve in the induction pipebetween the throttle valve and the cylinders and means to open saidvalve, when the vacuum in the induction pipe exceeds normal idle runningvacuum, said means comprising an electromagnet with an armatureconnected to said valve and a vacuum gauge, connected to the inductionpipe and controlling the circuit,

through which electric current is furnished to the said magnet,-and asnap mechanism,

serving to lock the said valve in open position, said snap mechanismcomprising an elect-romagnet with a spring actuated armature, theelectric circuit of which is closed by a relay influenced by the speedof the motor.

3. An apparatus for preventing the formation of a vacuumin the cylindersof an internal combustion engine when the throttle valve is closed,comprising an opening, closed by a valve in the induction pipe betweenthe throttle valve and the cylinders and means to open said valve, Whenthe vacuum in the induction pipe exceeds normal idle running vacuum,said means comprising an electromagnet with an armature connected tosaid valve and a vacuum gauge, connected to the induction pipe andcontrolling the circuit, through which electric current is furnished tothe said magnet, and a snap mechanism, serving to lock the said valve inopen position, said snap mechanism comprising an electromagnet, thevoltage supply to which is supplied through the current relay on theusual generator.

4. An apparatus for preventing the formation of a vacuum in thecylinders of an internal combustion engine when the throttle valve isclosed, comprising an opening, closed by a valve in the induction pipebetween the throttle valve and the cylinders and means to open saidvalve, when the vacuum in the induction pipe exceeds normal idle runningvacuum, said means comprising an electromagnet with an armatureconnected to said valve and a vacuum gauge, connected to the inductionpipe and controlling the circuit, through which electric current isfurnished to the said magnet, and a snap mechanism, serving to lock thesaid valve in open position, said snap mechanism comprising anelectromagnet with a spring actuated armature, the electric circuit ofwhich is closed by a relay influenced by the speed of the motor and by acontact mechanism, operated by the gas pedal.

5. An apparatus for preventing the formation of a vacuum in thecylinders of an internal combustion engine when the throttle valve isclosed, comprising an opening, closed by a valve in the induction pipebetween the throttle valve and the cylinders and means to open saidvalve, when the vacuum in the induction pipe exceeds normal idle runningvacuum, said means comprising an elect-romagnet with an armatureconnected to said valve and a vacuum gauge, connected to the inductionpipe and controlling the circuit, through which electric current isfurnished to the said magnet, and a snap mechanism, serving to lock thesaid valve in open position, said snap mechanism comprising anelectromagnet with a spring actuated armature, the electric circuit ofwhich is closed by a relay influenced by the speed of the motor, theelectric circuits of the two electromagnets above mentioned passingthrough contacting mechanisms, which will causethe electric circuits tobe broken, as soon as the action of the electromagnets has beencompleted.

6. An apparatus as claimed in claim 2, characterized by this that themain magnet controls the valve by a lever and a disk with teeth whichmesh with a pinion on the spindle of the valve and that the valve islocked in open position by means of a hook, which is arranged for thispurpose to engage with a notch in the disk.

7. An apparatus as claimed in claim 2, characterized by this that themain magnet controls the valve by a lever and a disk with teeth whichmesh with a pinion on the spindle of the valve and that the valve islocked in open position by means of a hook, which is arranged for thispurpose to engage with a notch in the disk, and that the hook isconnected with an armature in a releasing magnet in such manner that itis brought out of enga ement with the notch, when current is supp ied tothe releasing magnet.

8. An apparatus as claimed in claim 2, characterized by this that themain magnet controls the valve by a lever and a disk with teeth whichmesh with a pinion on the spindle of the valve and that the valve islocked in open position by means of a hook, which is arranged for thispurpose to engage with a notch in the disk, and that the hook isconnected with an armature in a releasing magnet in such manner that itis brought out of engagement with the notch, when current is supplied tothe releasing magnet, the said releasing magnet and its various partsbeing insulated from the remainder of the apparatus, when the valves areclosed.

9. An apparatus as claimed in claim 2, characterized by this that themain magnet controls the valve by a lever and a disk with teeth whichmesh with a pinion on the spindle of the valve and that the valve islocked in open position by means of a hook, which is arranged for thispurpose to engage with a notch in the disk, and that the hook isconnected with an armature in a releasing magnet in such manner that itis brought out of engagement with the notch, when current is supplied tothe releasing magnet, the said releasing magnet and its various partsbeing insulated from the remainder of the apparatus, when the valves areclosed, and the said hook bearing against an insulating plate on thesaid disk, when the valve is closed.

EINAR ISDAHL.

